Two in one gas and fire alarm



March 29, 1955 A. L. SHAFER TWO IN ONE GAS AND FIRE ALARM Filed June 26, 1951 Fig.4

United States Patent TWO IN ONE GAS AND FIRE ALARM Albert Louis Shafer, Salem, Ohio Application June 26, 1951, Serial No. 233,571

1 Claim. (Cl. 340-437) The present invention relates to a gas and fire alarm and it consists in the combinations, constructions and arrangements of parts herein described and claimed.

Generally there is provided a gas and fire alarm which consists of a casing in which is mounted a suction motor which directs a flow of air through a tube at a plurality of propeller blades which are mounted upon a shaft and which, in turn, act to move a needle in conjunction with a dial upon which there is indicia indicating good air and poor air. The device may be adjusted so that good air is indicated when of a certain specific gravity and poor air will be indicated when the specific gravity changes due to the fact that gases or smoke have been added thereto. When the dial reaches a certain point upon the poor air side thereof, an alarm is sounded.

It is accordingly an object of the invention to provide a device of the character set forth which is simple in construction, inexpensive to manufacture and yet effective and etficient in use.

Another object of the invention is the provision of a novel gas and fire alarm.

Other and further objects of the invention will become apparent from a reading of the following specification taken in conjunction with the drawing, in which the Figure 1 is a vertical sectional view, partly in elevation, of an embodiment of the invention.

Fig. 2 is an elevation view of governing means used in the device.

Fig. 3 is a plan view of a dial and needle used in the device.

Fig. 4 is a wiring diagram of an electric coll circuit used in the device.

Referring more particularly to the drawing, there is shown therein a gas and fire alarm having a casing in which is mounted a frame 11 and in which is mounted a double conical frustrum having its enlarged portion in the center and upon one of the cones 12 of which is mounted a suction motor 13 from which leads a tube 14 which extends through the frame 11 and the smaller part of the cone 12 and which terminates, as indicated at 15, adjacent a plurality of propeller blades 16 mounted upon a shaft 17 which extends centrally and vertically in the casing 10.

The shaft 17 is mounted in an oilless bearing 18 and provided with a spring 28 mounted adjacent such bearing, and having its upper end portion extending through a bearing 31 and the frame 11. The upper end of such shaft being adapted to move a needle 20 attached thereto in an arcuate path over a dial upon which is indicated, respectively, good air and poor air."

Upon the upper and outer side of the casing an alarm bell is aifixed and connected by means of wires 33 with batteries 26 installed within the casing and frame. The alarm bell 25 is adapted to be sounded whenever the needle 20 swings to the portion for poor air on the dial.

The cone 24 is open at its smaller end and adapted to 2,705,315 Patented Mar. 29, 1955 discharge air through a plurality of openings 27 in the portion of the casing adjacent thereto.

In operation it will be observed that the suction motor, or pump 13 has a connection 30 through which air is drawn by the motor through the end portion of the casing which has a plurality of apertures 38 and will cause such air to emanate in jets from the free end. 15 of the tube 14, connected with the said suction motor, and impinge upon the blade 16 whereby to revolve the same and the 0 shaft 17 and, through conventional means, to move the needle 20 in accordance with the specific gravity of the air being pumped therethrough. Should the air become heavier than is natural the blades will, of course, revolve more rapidly and thereby move the needle 20 to the point adjacent the indicia 22 whereupon, through conventional means, the alarm bell 25 will be sounded to thereby warn persons in the area that a fire or gas exists in the vicinity.

In Figs, 2, 3, and 4, there is shown a shaft 17 having arms 22 and the balls 21 of a governor, a standard 23, a brace 24, a lever 28, nut 29, and a cam 30 in the rod 17 engaging a cam 31 on the pointer 20 which carries a contact 32 which is connected by wire 33 to a battery 26 also connected by wire 33 to a contact terminal 34 in circuit with an electric bell 34. In Fig. 3 is shown a spring 36 having a guide 35.

In Fig. 2 is shown a coiled spring 37 encircling the shaft 17.

While but one form of the invention has been shown and described herein, it will be readily apparent to those skilled in the art that many minor modifications may be made without departing from the spirit of the invention or the scope of the appended claim.

What is claimed is:

A device of the class described comprising a housing having a fiat bottom surface and a frame disposed therein, a double conical frustrum mounted in: said frame and with the apexes in horizontal alignment with each other and the bases adjacent each other, a vertical shaft extending vertically through the line of juncture of the said bases and having its end journaled in opposite sides of the frame, a plurality of air movable blades affixed vertically on said shaft, an air suction motor affixed on the top surface of one side of said frustrum, :a discharge pipe having one end connected to said motor and its opposite end extending through the end of one side of said frustrum and terminating adjacent said blades, said casing having a plurality of air vent openings in said casing adjacent the apex of the one said frustruin, the means for discharging air from same, an indicia bearing dial mounted in the upper portion of said housing, an indicating needle associated with said dial said needle being connected moveably with said shaft and operable by the speed of rotation thereof, and an alarm bell mounted on the upper surface of said housing and connected within an electrical circuit and said bell being activated by reason of said needle being moved into a certain portion of said dial.

References Cited in the file of this patent UNITED STATES PATENTS 1,047,960 Malinovszky Dec. 24, 1912 1,133,556 Gerdien Mar. 30, 1915 1,292,334 Larsen Jan. 21, 1919 1,603,924 Rossman Oct. 19, 1926 2,472,609 Moore, Jr June 7, 1949 2,602,330 Kollsman July 8, 1952 FOREIGN PATENTS 492,973 Great Britain Sept. 30, 1938 

